The use of graffiti to deface various types of surfaces is wide spread both in cities of the United States of America and cities of many other industrialized world nations. Graffiti can consist of any unauthorized name, word or symbol or any combination thereof that is placed on a public or private surfaces by so called "graffiti taggers". Graffiti taggers have been around and have marked public surfaces since the days of the Pharaohs--even the pyramids did not escape this aesthetic plaque. Today, there is hardly a blank wall in inner cities, such as in central Los Angeles, that does not display some form of graffiti.
The primary target areas for graffiti taggers include public and private businesses, street and freeway signs, subways, trains and buses. To curtail the application of graffiti, several plans, devices and activities have been implemented: In Los Angeles, for instance, 4,000 people participated in a graffiti paint-out spearheaded by the Los Angeles Police Department. In one morning, the volunteers used 1700 gallons of paint and eradicated 62,000 feet of graffiti. The work of both public and private graffiti cleanup efforts are evident across the city in patchwork squares of unmatched paint on walls and buildings. As well meaning as cleanup techniques are, statistics have shown that when graffiti are covered in patches, the patches are invitations to graffiti vandals. Thus, graffiti is three times as likely to reappear then if the wall were all one color. To prevent street and particularly high-rise freeway signs from being marked razor wire has been placed around the signs access areas. The Transit Authorities of the various cities have taken cars out of service for cleaning as soon as they were marred by graffiti, no matter how slight the marking. Guards and dogs have also been posted in yards where these vehicles are stored for cleaning and maintenance.
To implement graffiti removal and watch programs has been costly for city governments. Most of the money goes to pay for crews that respond to the complaints by homeowners and businesses. Last year, the Los Angeles county government spent over $10 million trying to clean up the graffiti. The city of Los Angeles spent another $4 million, and the Southern California Rapid Transmit district spent $5 million. These figures are in addition to the money spent by various police agencies in chasing and arresting graffiti taggers. In New York, the Transit Authority has spent $6 billion in subway cleanup campaigns. Workers spend an average of 110 hours a week cleaning spray-paint off subway cars. In subways, it has been estimated that the national cost for controlling graffiti will exceed $4 billion. In addition to the cost involved in trying to eradicate graffiti, there is also the cost involved in decreased property values and in the more intangible psychic costs of living in a city that looks as though it is under siege.
Graffiti taggers use ballpoint pens, felt-tip markers and aerosol spray cans to perform their work with spray cans being the marker of choice. Over the years there have been various efforts to control graffiti by clamping down on the use of aerosol pain spray cans. According to the paint industry about 41,400 of these paint spray cans with a retail value of $120,000 are sold each day in Los Angeles, Orange, Riverside and San Bernardino Counties. By another estimate, more than 8,000 of these spray cans are used daily to deface property nationwide. To curtail the adverse use of spray cans, laws have been passed or are in process of passage to keep spray cans locked up, marking these cans unavailable for purchase by persons under the age of 18 and even to ban the sale of spray paint cans statewide, except those used by commercial firms. An outright ban is, of course, unfair to both the manufacturers and retailers--and most likely ineffective.
A search of the prior art did not disclose any patents or other literature that read directly on the claims of the instant invention. Particularly, no patents were found that disclosed aerosol paint spray cans that can only be operated when connected to a utility power source. However, the following U.S. patents were considered related:
______________________________________ U.S. PAT. NO. INVENTOR ISSUED ______________________________________ 5,014,884 Wonsch 14 May 1991 4,972,975 Fuhrig 27 November 1990 4,971,257 Birge 20 November 1990 ______________________________________
The Wonsch U.S. Pat. No. 5,014,884 discloses an aerosol spray can that includes a spray mechanism for finely atomizing fluids through a hydraulically-operated pump. The spray mechanism is inserted into a housing which is connected with the supply container for the liquid through a close-fitted or frictional locking connection. The spray mechanism incorporates a battery operated gear pump in which, the suction line of the pump is connected through an opening in the bottom of the housing into the supply container. The supply container is equipped with a venting line, whereby the gear pump includes a pressure tube at its output which is connected with a discharge nozzle.
The Fuhrig U.S. Pat. No. 4,972,975 discloses a housing that stores a battery that powers an electric motor that operates a compressor for producing compressed air in combination with a suction unit and a pressure joint. A product container that includes a spray nozzle is placed inside the housing with a connection between the pressure joint of the compressor and the interior of the product container. The compressor pressurizes the product container through an aperture thereby forcing the liquid through the container spray nozzle.
The Birge U.S. Pat. No. 4,971,257 discloses an electrostatic particle spraying apparatus. The apparatus includes a hand held triggering mechanism that includes a d-c power source and a coupling sleeve into which a conventional aerosol spray can is inserted when the triggering mechanism is squeezed, a hammer depresses the nozzle tip of the aerosol can, releasing the pressurized fluid of the can from the nozzle tip.
This application is also related to the applicant's copending application Ser. No. 08/095,851, filed Jul. 23, 1993 and entitled Utility-Power Operated Aerosol Spray Can.
For background purposes and indicative of the art to which the invention relates, reference may be made to the following remaining patents found in the pre-examination search:
______________________________________ PATENT NO. INVENTOR ISSUED ______________________________________ 5,069,391 Seasholtz 3 December 1991 4,618,099 Nagad et al 21 October 1986 ______________________________________